Gasket



Patented-Ma 23, 1944 UNITED STATES PATENT OFFlCE Q 2,349,235 Q I Y I GASK.ET wilbum F. Bernstein. Brookiield, astepmnrr; Lillis, Chicago, Ill assigiiors to Victor Mauuiacturing & Gasket Go corporation of Illinois ,No'lirawing. Application July 16, 194 Serial No. 402,716

,1 Claim. ass-an The present invention relates to a novel gasket adapted for use in automobiles and other power propelled vehicles and particularly for use with mpany, Chicago, a

of thewater'the protoplasmic material that is the living 'matter of the sponge dies and dries comprises a base of sponges'picules bonded by a flexible binder and forming therewith aneffective seal against the leakage or passage of oil,

grease, water and other-coolingfluids, general industrial fluids, alcohol, glycerin and other antifreeze liquids orsolutions at elevated temperatures. This material-further has s'uflicient inherent elasticity as to maintain its resiliency and sealing characteristics against the compression of the fastening means when placed and clamped between members to be sealed, and to retain its original shape and dimensions against humidity changes as well as contraction and expansion due to temperature changes.

Heretofore it has been the general practice to make gaskets from sheets of material previously treated and/or so fabricated that after gaskets out leaving the highly absorbent skeletal structure commonly thought of as the ordinary sponge usedfor-cle'aning' purposes. In the sponge industry'there is a tremendous amount of clippings of misshapen sponges and scraps of the sponge skeleton which are available in large quantities and-are considered either as scrap or of very little value. When these scraps or clippings are thoroughly cleaned and run through a I hammer mill, the skeletal structure is reduced to r materials such as silica and carbonated lime, and

, retain their original resiliency andthe elastic have been blanked therefrom the unused portions are scrapped. Such unused or scrapped portions may comprise approximately sixty'per cent or more of thetotal sheet and represent a considerable loss and an important factor in the ultimate cost of the gaskets so produced.

Gaskets of the types referred to have been generally composed of cork. As this material is secured from a European source, its importation at the present time is a serious problem and great difficulty is had in securing a supply for the many uses in which cork gaskets are now employed.

Although cork has been so widely used as a gasketing material, it has numerous disadvantages in that it has insufflcient resistance to heat, oil and other fluids, lacks strength and flexibility, is affected by weather conditions and changes its dimensions due to humidity and temperature changes, is relatively expensive, and

has a high percentage of loss due to scrap.

The present invention further relates to a novel interlacing fibers. When the sponge is taken out characteristics of the original skeletal structure of the sponge. f

After the cleaned sponge has been reduced to the substantially individual spicules; these spicules are ready for compounding with suitable binders to form a material having characteristics .which make it ideal for use as gaskets. Numerous ways have been found in which binders suitable for the purpose may be combined with the sponge spicules, and excellent results have been secured by the use of a binder composed of synthetic rubber and sulfurized oil combinations, although we have also employed binders composed of resins (both thermosetting and thermoplastic), natural rubber, natural rubber and resin combinations, reclaim rubber and resin combina-- tions', synthetic rubber, orsynthetic rubber and resin combinationts. One highly successful binding 'formula'consists of the following ingredients in approximately the following prnportions:

The sulfurized oil and coal tar act as softeners while the zinc oxide, benz o. thiazyl disulfide and butyl zymate act as accelerators, the latter permitting the binder to cure-at room temperature. The sulfur acts as a curing agent while the phenyl betanaphthylamine acts-as an anti-oxident.

The binding material as outlined above is mixed in a Banbury mixer and to this mix i then added the desired amount of sponge spicules. The resultant mass when thoroughly mixed is sheeted on an ordinary rubber mill and calendered into sheets of the desired thickness and dimensions [for use in blanking gaskets. The sheets so produced may be cured in sheet form b open air vulcanization and placed between platens of a hydraulic press, or by steam curing. Gaskets may be blanked from the uncured sheets, held on forms so that they will maintain their shape, and then cured in either of theabove manners. Or, gaskets after being blanked from the uncured sheets, may be placed on forms and permitted to stand for a period or approximately 48 hours in a warm place. This period is sufilcient for the gaskets to cure themselves by reason of the incorporation therein oi. an ultra-accelerator such as butyl zymate which will cause curing at room temperature. I

By the use of the above binding material and the mixing in a Banbury mixer of this binder with a substantially equal proportion of sponge spicules. a resultant stock is produced which makes excellent gaskets. It has excellent oil and water absorption characteristics and has the distinct advantage over cork of being more heatresistant and flexible. It is more economical than cork in that it may be blanked and cured with no loss in scrap, as all scrap can be re-milled, resheeted and re-blanked. The gaskets produced from this material have superior resiliency to that of cork, a property highly important in sealing. Such gaskets have superior oil, gasoline and water resistance and will withstand greater heat over longer periods of time than will cork gaskets. Furthermore, the present gaskets are not adversely affected by weather conditions and have superior aging resistance to that of cork.

Although we have mentioned that substantially equal parts of sponge and binder may be pre- 5 ferred, excellent results have been secured by varying the portions 01 these ingredients from approximately 60% spon e and 40% binder to approximately 90% binder and sponge. It will be readily undersood that the greater the proportion of binder the more expensive the resultant gasket. Furthermore, in the binder formula good results have been secured by varyin 'the proportions of the butadiene polymer, sulfurized oil and coal tar. For example, beginning 1:, with substantially equal parts of butadiene acrylonitrile copolymer and suliurized oil, these proportions maybe varied through a wide range to a point where only butadiene acrylonitrile copolymer is used. Likewise, the coal tar may be varied between a lesser and greater amount than that recited in the above formula. Although the particular example given mentions polymerized butadiene as a form of synthetic rubber, it will be readily appreciated that other synthetic rubbers such as polymerized chloroprene, polyvinyl chloride, rubber hydrochloride, etc., may be employed.

Having thus disclosed the invention, we claim: A compressible, impervious gasket having sub ficient inherent elasticity as to retain its resiliency and sealing characteristics against the com-- pression or fastening means when placed and clamped between members to be sealed, consist" ing of individual fiber-like sponge spicules and a resilient binder filling the spaces between the spicules.

WILBURN F. BERNS'I'EIN. STEPHEN M. LILLIS. 

